Various feature-based methods for finding the position of mobile users or terminal devices in wireless communication networks are known from the prior art. As features, for example, the field strengths of fields through the mobile object are measured, the fields being generated and emitted in the communication network by a plurality of base stations. As communication networks, for example, DECT networks (DECT=Digital Enhanced Cordless Telecommunications), WLAN networks (WLAN=Wireless Local Area Network) and the mobile radiocommunication networks GSM (GSM=Global System for Mobile Communication) and UMTS (UMTS=Universal Mobile Telecommunication System) are used.
In feature-based position finding, so-called reference maps are used in which, for a multiplicity of support points, a relationship between the spatial position of the support point and feature-dependent variables of the individual base stations is filed. Feature-dependent variables in a field-strength-based method are, for example, the field strength of the field emitted by a base station at the spatial position of the support point or the field strength, measured at the base station, of a field that is emitted by an object which is located at the spatial position of the support point. By measuring the field strength at any position and by comparing the measured value with the field-strength-dependent variables at the support points on the reference map, the position of the object can be determined. In the field-strength-based method known from the prior art, a calibration or gauging of reference patterns is necessary in order to achieve sufficient accuracy in structured environments. This calibration is labor- and cost-intensive, and the greater the accuracy desired, the more time-consuming it is.
Besides calibration using reference patterns, it is also known from the prior art for the position of the most powerfully receiving base station to be determined in the mobile object by means of simple trilateration models, for example assuming a radial field propagation. In such methods, few parameters are needed, and these can be adjusted by means of few reference measurements. However, these methods have the disadvantage that the accuracy they achieve is significantly lower than in methods in which a reference map is created by means of a multiplicity of measurements.